Trichia varia a Slime Mould
I found this colony on the inner wood of a very rotten Silver Birch tree, They start off white and change to yellow.
The field of view is about 3mm wide.
Olympus EM-1 (manual mode), Olympus 4/3 x2 TC, Olympus 4/3 50mm f2 macro, f8 ISO 320, twin flash hand-held.
Olympus EM-1 (manual mode), Laowa 25mm f2.8 2.5x-5x ultra-macro at f8 ISO 320, triple TTL flash hand-held.
The stereos are crosseye.
Dark brown plasmodium: